1. Field of the Invention
The present invention relates to an in-vivo information acquiring system which acquires information inside a subject.
2. Description of the Related Art
Recently, a swallowable capsule endoscope has been developed in a field of endoscope. The capsule endoscope has an imaging function and a wireless transmission function. The capsule endoscope is introduced from a mouth of a patient for observing a body cavity, and sequentially picks up body cavity images of organs such as an esophagus, a stomach, and a small intestine moving with peristalsis until naturally excreted (e.g., see Japanese Patent Application Laid-Open No. 201-231186).
Image data which is captured inside a body by the capsule endoscope moving through the body cavity is transmitted to an outside of body via wireless transmission. Then, the image data is stored in a memory arranged in a receiving apparatus outside the body. Doctors and nurses can make a diagnosis using images displayed on a display based on the image data stored in the memory.
The common capsule endoscope described above used to be a monocular capsule endoscope which captures body cavity images in a forward direction of movement. Recently, however, a binocular capsule endoscope which captures images in both forward and backward directions of movement for widening a visual field and the like has been proposed (e.g., see US Patent Application Laid-Open 2004/199061). The binocular capsule endoscope has a structure where plural imaging units each of which has a pair of imaging devices such as an LED for illuminating a body cavity and a CCD for capturing body cavity images are arranged at both front and rear ends of the capsule endoscope to capture the images in a direction of movement of the capsule endoscope inside the body cavity.
A capsule endoscope system wirelessly transmits the image data captured by the capsule endoscope, for example, in a data structure similar to that of NTSC transmission of image. Specifically, the capsule endoscope processes the image captured by each imaging unit by a unit of scan-line data. The capsule endoscope wirelessly transmits first scan-line data using a vertical synchronization signal, and each following scan-line data using a horizontal synchronization signal. Further, the capsule endoscope transmits last scan-line data to which unique information indicating the imaging unit that has captured the image is attached, thereby finishing transmitting data corresponding to the single image. Receiving the entire scan-line data, the receiving apparatus processes the unique information attached to the last scan-line data, and identifies which imaging unit has captured the image formed by the series of received scan line data. Thus, the receiving apparatus receives the single image.